There are various applications in which a plurality of pressure fluid actuators are required to co-operate to apply an optimum control pressure, for example, in clutch or brake systems, as used in the paper converting industry. A multi-range facility can be obtained by provision for manual selection of a desired number of actuators, to obtain optimum control. It would however be advantageous to provide a condition responsive control system for use in particular where control arrangements cannot be readily accessible, or where frequent changes are required.
It is accordingly an object of the invention to provide a system for controlling communication of pressure fluid to one or more of a plurality of outlets in dependence on the pressure of the fluid.
It is also an object of the invention to provide such a system which operates solely by means of pressure fluid.
It is a further object of the invention to provide a system for controlling the condition of a valve communicating a pressure fluid source with an outlet in response to the valve of the pressure of the pressure fluid as compared with one or more reference pressures.
It is an additional object of the invention to provide a control system for a plurality of fluid outlets, whereby the outlets are opened or closed to supply or cease to supply a pressure fluid in response to predetermined fluid pressure conditions in a predetermined order.